A pallet is a portable, horizontal, rigid, platform used as a base for assembling, storing, stacking, handling goods as a unit load. Conventional pallets are typically constructed of wood and are made by stapling or nailing a number of boards (known as "deckboards") at their ends to a number of continuous solid boards (known as "stringers"). The upper set and lower set (where used) of deckboards thereby form an open area defined by the thickness of the stringers. This opening is used to accommodate a fork lift or hand truck. In this way the pallet may be moved from place to place by lifting the pallet and its load off the floor.
The vast majority of all pallets used in the U.S. are constructed of wood, but wood pallets have many disadvantages. Labor and material costs for wooden pallets have increased faster than inflation. Because of their expense, the pallets are often reused or returned to their place of origin. The cost of returning empty pallets to their owners is obviously high. Additionally, the average weight of a wooden pallet is about forty pounds. Since shipping costs are usually tied to the weight of the goods shipped, the cost of shipping is increased by the weight of the pallet. Indeed, pallets are sufficiently heavy that smaller warehouse workers are able manually to move the pallets only with some difficulty. Wooden pallets are often damaged during use and, because of the pallet cost, must be repaired if possible or disposed of. Depending upon the industry involved, pallets may be used between two and four times before they are disposed of. Disposal of any solid materials including broken pallets is an increasingly difficult and costly problem.
My invention is a pallet constructed of paper involving a central platform or deck constructed of a honeycomb filler. The bottom of the pallet is covered by a combination of sheets (which may be corrugate) which are patterned in such a way that the footblocks supporting the central platform are integral with that central platform; that is, the footblocks (or legs) do not have a seam at their juncture to the central platform. Desirably the lower portion is formed of two sheets; one sheet ("the bottom or lower cover") is cut and folded in such a way that the legs and the surface adjacent the bottom of the central portion are of the shape in which the pallet is finally used. The other sheet ("lower or bottom facing sheet") is of the general size and shape of the bottom of the central platform with cutouts allowing the footblocks (covered by the bottom cover sheet) to protrude through that lower facing sheet. It is positioned adjacent the bottom surface of the central platform. The upper surface of the central platform is covered with a generally continuous sheet ("the upper facing sheet"). The upper facing sheet may be a corrugate or heavy stock paper depending upon its ultimate usage. To enhance the torsional and deflective strength of the central platform and thence that of the pallet, a corrugated sheet may be used as the upper facing sheet and positioned so that the corrugations of the upper facing sheet and those of the lower facing sheet are not parallel. Additionally, the various corrugated sheets may be folded over the edges of the honeycomb core and fastened to another other surface. In addition to the inherent strength and low cost of my pallet, by careful selection of construction materials, my design may be completely recycled as paper without separation into constituent parts.
There are a number of pallet designs which are made mostly of paper.
For instance, U.S. Pat. No. 3,661,099, to Shelor, shows a paper shipping pallet having a deck having a core section made of small strips cut from single, double, or triple wall corrugated paper board sheet stock glued face to face. Sheets of corrugated are glued to the longitudinal edges of the composite core. The core and facing sheets are desirably of a specific size of corrugated sheets, i.e., having a size "A" flute or better. The legs of the pallet appear to be wooden blocks.
U.S. Pat. No. 3,650,459, to Tucker, shows a paper pallet design involving a folded corrugate sheet as the cargo support area. That cargo deck is provided with a number of pallet feet (which operate as spacer blocks within the cargo deck) made of molded plastic material such as polystyrene. The use of a honeycomb core within the cargo support area is not disclosed.
U.S. Pat. No. 3,952,672, to Gordon et al, shows a disposable pallet made of a single folded corrugated sheet. The use of a honeycomb core on the cargo support area is not disclosed.
U.S. Pat. Nos. 4,867,074 and 5,001,991, to Smith, each show a pallet design in which the cargo deck is made up of a large number of girders folded from corrugated sheet and assembled with a series of cross girders. The use of a honeycomb core in the cargo support area is not disclosed.
U.S. Pat. No. 4,790,249, to Webb, shows a pallet design in which the cargo deck is made up of facing sheets separated by a number of blocks having a specific design. The block design involves a cellulosic material glued together by a bonding material (such as ureaformaldehyde) all extruded into the shape of a box beam. The boxes are positioned so to protect the deck from the tines on a fork lift.
Netherlands Patent Application 83-00024 shows an interesting design for a paper pallet. The cargo support deck appears to be constructed of a number of loops of paper glued together at a number of sites within the deck and also glued to a periphery forming the edge of the deck. Neither the use of a honeycomb core nor the use of corrugated sheet in the cargo deck support area is disclosed.
There are few disclosures showing the use of honeycomb materials in the core of the cargo support deck.
One such disclosure is Published U.K. Patent Application 2,213,462-A to Green et al. This published application shows a paper pallet design in which the cargo deck is made up of two face sheets of, e.g., corrugated cardboard and having an open structure such as a paper or card honeycomb between them. It is said that the deck may be raised from the floor using feet of similar construction. The deck core is made to be penetrable by the tines of a fork lift. There is no suggestion that the corrugated sheets on alternate sides of the core should be positioned so that the flutes are not parallel. Furthermore, the disclosure is silent on the use of a corrugated sheet folded over the edge of the central core and fastened to the opposite side, and the disclosure does not suggest legs which are integral with the skin on the central core.
U.S. Pat. No. 4,319,530, to Moog, discloses a pallet, said to be disposable, having a cargo supporting deck area made up of a central core of a honeycomb made of laminated corrugate. The core is faced with one or more corrugated sheets glued to the core. The facing on the cargo support surface of the central core may be made up of multiple layers of corrugated sheets. Although these multiple facing layers are said to be positionable so to permit "cross laminating where the flutes of the different sheets are oriented at right angles", there is no suggestion that use of corrugated sheets on alternate sides of the core positioned so that the flutes are not parallel is useful. Further, the disclosure is silent on the use of a corrugated sheet folded over the edge of the central core and fastened to the opposite side nor, obviously, is any benefit accorded such a folded sheet.
None of these disclosures show a pallet constructed of paper involving a central platform or deck constructed of a honeycomb filler bounded on the top and bottom surfaces by corrugated sheets nor do these disclosures show the concept of using a folded corrugated sheet as both the skins on the individual legs supporting the central core and on the bottom of the central core itself. These disclosures do not show the benefit of increased torsional and deflective strength of the central platform via the use of carefully positioned corrugated sheets such that the corrugations or flutings in those face sheets are not parallel.